Should you be double-masking? It depends
March 1, 2021
As more variants of the COVID-19 virus continue to emerge — some much more contagious than the original strain — we’re all looking for ways to stay safe and keep ourselves and our loved ones protected from infection. Double-masking, or wearing two masks layered on top of each other, has become a popular strategy for making cloth masks more protective against SARS-CoV-2, the virus that causes COVID-19. But is double-masking actually necessary?
It depends on several factors. Double-masking, as a general practice, doesn’t add much to the protective power of a face mask. It’s much more important to focus on the fit of your mask: One well-fitting mask will protect you better than two loose-fitting, layered masks. An ill-fitting mask, whether it be medical-grade or cloth, will leave you vulnerable to the virus.
What is considered a well-fitting mask? It’s different for each individual. Overall, you want your mask to be snug enough to not fall off or gape when you talk or move, but not so tight that it hurts or leaves marks on your skin.
The Centers for Disease Control and Prevention (CDC) recently weighed in on the subject of double-masking, and, similarly, emphasized the importance of adjusting the fit of your mask to be snug against your face.
What to look for in a cloth face mask
If you have a well-fitting cloth mask made of multiple layers of tightly woven cotton, then you shouldn't need to add another on mask on top of it. To power up your single mask’s protection:
- Make sure you’re wearing a mask made of at least two to three layers of tightly woven cotton.
- Avoid stretchy fabrics that can lose their shape over time or fabrics, such as fleece, that are not tightly woven.
- Make sure your mask fully covers your mouth, nose and the sides of your face.
- Find a mask with a nose bridge that can conform tightly to your nose shape and keep the mask from gaping.
- Avoid neck gaiters and bandanas since they are not form-fitting enough.
- If the loops on your mask are too loose, use bands or knots to tighten them.
Double masking and medical masks
Medical-grade masks include regular “surgical” masks and fitted masks like N95s or KN95s. Fitted masks should really only be worn by individuals who have been formally fit-tested for the masks to ensure optimal protection. Without having a fit test, it’s possible these masks are not providing their full filtering capabilities. Because these masks are disposable, but often hard to find or keep in stock, some people wear a fabric mask on top of a fitted medical mask to protect it from the environment and keep it cleaner for longer.
Regular (non-fitted) medical masks, known as surgical masks or procedure masks, have variable filtering capacity that is largely dependent on the fit. The CDC found that layering a cloth mask over one of these masks improved filtration, mostly because it reduced gaping that let in air particles. Flattening the sides of the medical mask and tightening the ear loops for a more snug fit also improved its effectiveness. Don't wear two procedural masks at the same time, though, because the fit is not improved.